4883-60-7Relevant articles and documents
Opening of epoxide rings catalyzed by niobium pentachloride
Constantino, Mauricio Gomes,Lacerda Jr., Valdemar,Invernize, Paulo Roberto,Filho, Luiz Carlos Da Silva,Da Silva, Gil Valdo Jose
, p. 3529 - 3539 (2008/03/13)
The behavior of several epoxides when treated with NbCl5 was studied. In general, the studied epoxides reacted rapidly with NbCl5, giving, in most cases, more than one product (chlorohydrins, products containing solvent residues, as well as rearrangement products). A detailed study was performed to verify the effects of the temperature (rt, 0°C, or -78°C) and of the NbCl5 molar concentration on the composition of the products, yield, and time required for the reactions. Copyright Taylor & Francis Group, LLC.
Practical preparation of diosphenols by ring opening of α,β-epoxyketones catalyzed by silica gel supported acids
Zhu, Rui,Xing, Lixin,Wang, Xinyan,Cheng, Chuanjie,Liu, Bo,Hu, Yuefei
, p. 2267 - 2271 (2008/02/09)
The mixed acid (H2SO4-HOAc) catalyzed ring opening of α,β-epoxyketone was the most used method for the preparation of diosphenols, but it seriously suffered from poor yields and tedious workup operations. By using silica gel supported mixed acid (H2SO 4-HOAc), a variety of α,β-epoxyketones were converted into the corresponding diosphenols in unprecedented high yields within a few minutes. Georg Thieme Verlag Stuttgart.
Niobium pentachloride catalysed ring opening of epoxides
Gomes Constantino, Mauricio,Lacerda Jr., Valdemar,Arag?o, Valquiria
, p. 770 - 776 (2007/10/03)
Epoxide ring opening is a frequently required transformation in Organic Synthesis. In this paper we describe the application of NbCl5 for this purpose using three different substrates. Chlorohydrins, 1,2-diols, products containing solvent resid
Conversion of α,β-epoxyketones to diosphenols using 6-methyl-2-pyridone anion as an hydroxide equivalent
Ponaras,Meah
, p. 9031 - 9035 (2007/10/03)
Treatment of α,β-epoxyketones with 6-methyl-2-pyridone anion gives diosphenol (6-methyl-2-pyridyl) ethers that can be cleaved to diosphenols under mild basic conditions. (C) 2000 Elsevier Science Ltd.
A New Synthesis of 3-Alkyl-1,2-cyclohexanediones from 2-Alkylcyclohexanones Using Iodine/Copper(II) Acetate
Horiuchi, C. Akira,Kiyomiya, Hiroshi,Takahashi, Masaaki,Suzuki, Yasuto
, p. 785 - 786 (2007/10/02)
The reactions of 2-alkyl-, 2,5-dimethyl-, and 3,3,5-trimethylcyclohexanone with iodine/copper(II) acetate in boiling aqueous acetic acid gave the respective 3-alkyl-, 3,6-dimethyl-, and 3,5,5-trimethyl-1,2-cyclohexanediones in 40-70percent yields.This new
IMPROVED SYNTHESIS OF 2-HYDROXY-4,4,6-TRIMETHYL-2,5-CYCLOHEXADIENONE, USEFUL AS A FLAVORING ADDITIVE
Buyck, Laurent de,Zi-Peng, Yao,Verhe, Roland,Kimpe, De Norbert,Schamp, Niceas
, p. 75 - 80 (2007/10/02)
The title dienone 1, useful for modification, improvement or increasing organoleptic properties of tobacco, sucrose syrups, flavored beverages, was prepared in 40-55percent overall yield from isophorone, by chlorination of 2-hydroxy-isophorone (2), rearrangement into 6-chloro-2-hydroxyisophorone (5) and dehydrochlorination.An excellent yield of 3-chloro-2-hydroxy-4,4,6-trimethyl-2,5-cyclohexenone (12) was obtained by chlorination of 5 followed by dehydrohalogenation.